Nuts and Bolts
Autopilots use magnetic headings to steer the boat. The system includes an electronic flux-gate gyroscope compass, a pump tied into the boat's hydraulic steering system, a processor and a control box. Data input, used to adjust the course, comes from either a rudder feedback mechanism attached to the outboard(s) mechanically or from rapid electronic pulses fed into the processor. The electronic system is becoming the preferred choice.